Since the strike call, reports speak of major traffic jams on Ukraine's western border where several main roads have been blocked, and some factories and universities are said to have stopped work.

However, coalminers in the east of the country, where Mr Yanukovych's strength lies, have vowed to work on.

Some analysts say the strike could further divide the country as Mr Yushchenko draws his support mainly from western and central regions.

Government supporters including several thousand miners have been holding rallies in Kiev but the capital is still dominated by Mr Yushchenko's supporters.

They have been camping out in Independence Square in freezing temperatures under orange banners.

'Enforced bias'

Ukraine's second national television channel, One Plus One, appears to have dropped the government line and begun broadcasting pictures of the demonstrations in Kiev.

The TV company said it had been forced to broadcast biased information but from now on it would be balanced.

"These principles will be adhered to as long as the channel is on the air," a presenter said before a news bulletin.

Leonid Kuchma, the incumbent president and an ally of Mr Yanukovych, has asked Polish President Aleksander Kwasniewski, with whom he has close ties, and the Lithuanian President Valdas Adamkus to mediate in the crisis.

Lech Walesa, a former Polish president and ally of Mr Yushchenko, has already gone to Kiev to try to help to resolve the crisis, saying he believes a compromise is possible.